I've experiencing black screen, video lag and frame freeze for a few seconds some times at place where signal was strong and without video link trouble before.
My current hypothesis is that it's related to high ambient temperature. Never had issues on cool days but some problems on hot ones. Generally, the first minutes everything is fine but bad video links arise afterward. Distance doesn't seem an issue : could happen with my P3P right next to me which make me think it's not a signal issue.
Just don't know if it's the P3 camera or the iOS device that is the culprit. Have had the symptoms on both an iPhone 6 and an iPad mini retina. Next time, I will switch the iOS device to check if the one that was just freshly started and colder is working better.
Maher